Genes may shape GLP‑1 response
A large genetics study examined nearly 28,000 people and identified gene variants that appear to influence how much weight someone loses on GLP‑1 drugs like Ozempic and Mounjaro. (earth.com).
Drugs that mimic gut hormones can cut appetite and slow digestion, and a new Nature study says inherited DNA differences help explain why weight loss on those medicines varies from person to person. (nature.com) Researchers at 23andMe analyzed self-reported data from 27,885 people who had used glucagon-like peptide 1 receptor agonists, including semaglutide and tirzepatide, and published the results on April 8, 2026. (nature.com) The study found a protein-altering variant in the GLP1R gene, which encodes the receptor targeted by these drugs, that was tied to greater weight loss: each copy of the variant was linked to about 0.76 kilograms, or 1.7 pounds, of extra loss over a median of eight months of treatment. (nature.com) The same paper linked variation in GLP1R and in GIPR, a second hormone-receptor gene, to nausea or vomiting on treatment. The GIPR signal appeared only in people taking tirzepatide, which hits both the glucagon-like peptide 1 and gastric inhibitory polypeptide pathways. (nature.com; 23andme.com) That helps explain a pattern doctors already see in clinics: some patients lose less than 5% of body weight on these medicines, while others lose more than 20%, and side effects range from none to persistent stomach symptoms. (23andme.com) The findings arrive as semaglutide products sold as Ozempic and Wegovy, and tirzepatide products sold as Mounjaro and Zepbound, have become central to obesity treatment in the United States and other countries. Nature’s paper describes the results as direct genetic evidence that variation in drug-target genes contributes to differences in response. (nature.com) Outside experts said the signal is real but the effect size is small. Marie Spreckley of the University of Cambridge said the extra weight loss tied to the GLP1R variant was “modest,” and that sex, drug type, dose, and treatment duration appear to explain more of the variation than genetics does. (sciencemediacentre.org) The study also has limits that matter for any future DNA test. The main dataset relied on self-reported weight, treatment duration, and side effects, and the cohort was mostly female and largely of European ancestry, which can skew results and make them harder to generalize. (sciencemediacentre.org) 23andMe said it has already folded the findings into a new report and interactive tool for members of its Total Health service. The paper itself is more cautious: it says the work lays a foundation for precision medicine, not a ready-for-clinic test. (23andme.com; nature.com) For now, the clearest takeaway is narrower than the hype around weight-loss shots: genes appear to nudge response, but they do not come close to determining it on their own. (sciencemediacentre.org; nature.com)
